Bodolphe messmer



R. M ESSMER ACOUSTIC DEVICE March 3, 1931.

Filed June 7. 1929 Inventor Attorneys Fatentecl Mar. 3, 1931 PATENT OFFICE RODOLPHE MESSMER, OF MONTREAL, QUEBEC, CANADA AQOUSTIC DEVICE Application filed June 7, 1929, Serial No. 369,197, and in Canada May 6, 1929.

The present invention relates to improvements in acoustic apparatus for speaking pulpits or the like.

An important object of the invention is the provision of an acoustic construction designed to effectively diffuse or distribute sounds from a predetermined position.

A further object of the invention is the provision of a covering or canopy having a plurality of acoustic units disposed to transmit the human voice through a wide speaking range of fre uencies.

A further obJect of the invention is the provision of sound transmitting apparatus ineluding a series of diaphragms having a vibration characteristic responsive to the sound wave energy of the human voice and a series of complementary diaphragms having a different vibration characteristic responsive to the vibration of the first named diaphragms.

Still another object of the invention is the provision of a speaking pulpit including acoustic apparatus attached to a stationary canopy and an adjustable platform disposed below the canopy whereby the source of sound wave energy from speakers of varying stature may be maintained at a fixed position with relation to the acoustic apparatus.

Another object of the invention is the provision of apparatus of the above character which will be simple and compact in construction and eflicient in use.

Other objects and advantages of the inven- 5 tion will become apparent as the description progresses.

In the accompanying drawing forming a part of this specification and in which like reference characters are employed to designate corresponding parts throughout the same:

Figure 1 is a vertical sectional view through a pulpit showing the canopy in elevation,

Figure 2 is a bottom plan view of the canopy and acoustic apparatus attached thereto,

Figure 3 is an enlarged vertical section through the canopy construction,

Figure 4 is a perspective view of an individual acoustic unit and supporting frame,

and

Figure 5 is a vertical section through the same. Referring to the drawing, wherein for the purpose of illustration is shown a preferred embodiment of the invention, the numeral 10 generally designates a pulpit canopy embodying a flat horizontal roof structure 11 attached to the upper extremity of a back Wall 12. To the front and side marginal portions of the roof 11 are connected vertically depending rails 13.

Attached to the under side of the pulpit roof portion 11 and depending downward ly therefrom are 'a plurality of box like frames 14-open at their lower ends and provided with corner extensions 15. Attached to and stretched tightly across the lower ends ofthe frames 14 are a series of horizontal diaphragms 16, preferably formed of skin loaded parchment or the like and having audible vibration characteristics responsive to the sound wave energy of the human voice; Each of the frames 14 carries one of the diaphragms 16,'the diaphragms being designed so that the complete set will embody a full speaking range of frequencies.

Attached to the lower ends of the frame extensions 15 are complementary diaphragms 17 formed of relatively rigid, preferably metallic material mounted parallel with and spaced from the upper diaphragms 16 by means of the spacer extensions 15. The diaphragms 17 are shaped to assume a corrugated leaf like form, as shown to advantage in Figures 2 and 3, .and are designed to distribute or diffuse the sound over a predetermined area, particularly a church or speaking hall of predetermined dimensions.

The lower portion of the pulpit embodies a stationary rectangular enclosure 18 mounted on the floor and arranged to fit within the rectangular formed front and side walls of a pulpit box 19. The pulpit box 19 is disposed in a vertical plane and attached to the corresponding edges of a horizontal platform 20. The platform 20 carries, on its under side, an anuular bearing collar 21 in which is rotatably fitted the upper extremity of a vertical screw shaft 22. The lower portion of the shaft 22 threadedly pro- (ill jects through a horizontally mounted gear 23 supported upon a bearing sleeve 24 and formed with peripheral bevel gear teeth.

The gear 23 meshes with a complementary vertically disposed bevel gear 25 secured upon the inner extremity of a drive shaft 26 journaled in an upright bearing plate 27 and carrying on its rear outer extremity a rotating crank 28.

The screw shaft and gears provide mechanism for vertically adjusting the platform 20 and side walls 19 attached thereto so that the platform may be adjusted in accordance with the varying height of speakers positioned thereon so that the source of vocal expression creating the sound wave energy may be constantly maintained at a fixed'position with respect to the acoustic units carried by the canopy.

In use, the sound waves produced by the vocal expression will vibrate the upper acoustic diaphragms 16 which are designed to embody an audible vibration characteristic. The vibration set up in the more sensitive diaphragms 16 will, by dynamic action, produce corresponding vibration of the complementary sound diffusing diaphragms 17 which are particularly designed to distribute the sound expression over a predetermined area. Therefore, the entire series of audible responsive and reproducing diaphragms can be constructed to include a wide, range of frequencies and will provide an acoustic effect of greatly improved qualities.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same, and that various changes as to the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described by invention, I claim:

1. An acoustic apparatus comprising a pulpit construction including a canopy, a plurality of acoustic units attached to the canopy disposed to reproduce and distribute the sound expression emanating from the pulpit, and an adjustable platform operable to compensate for the variant stature of speakers in the pulpit to maintain a constant distance between the source of vocal expression and-the acoustic units.

2. An acoustic apparatus comprising a pulpit'construction including a canopy, a plurality of acoustic units attached to the canopy disposed to reproduce and distribute the sound expression emanating from the pulpit, a vertically adjustable speaker supporting platform, and mechanism for selectively adjusting the position of the platform to compensate for the variant height of persons positioned on the platform to maintain hand.

RODOLPHE MESSMER. 

